From practice, hydraulic flow dividers, integrators and throttle regulators are known which divide the liquid flows in a predetermined ratio independent of loading, i.e. separate liquid flows are summed, so that the proportion of the velocity of labor-performing elements should have the same proportion of flow, independent of load. The versions of these structures, when provided with supplementary elements, e.g. with slide valves acting as releasable and connectable hydraulic differential locking devices, enable that at a given control signal, liquid flows could reach the driven members bypassing the regulating slide valve, without quantitative correction.
Further constructions are also known, with which elimination of regulation is performed by fixing the position of the regulating slide valve by an optional control signal, e.g. by the aid of control pistons. Compared to the previous solution, this solution has the advantage, in so far as large-sized by-pass channels become superfluous. The aforementioned solutions have the common characteristic, that liquid flows to be regulated are measured by means of constant measuring throttles or those changing in response to the liquid flow. Liquid flows passing the measuring throttles produce pressure signals, the difference of which displaces the regulating slide value if there is any, the deviation from the given ratio of division and integrating being such that cross-section of the proper pipelines are narrowed or windened until the differential pressure has ceased i.e. the desired quantitative ratio is reached.
The disadvantage of these solutions lies in that the systems work with a certain energy loss caused by the pressure drop arising in course of the travel of the liquid currents through the measuring throttles, although the systems with a changing meassuring throttle work with a more advantageous energy consumption and are able to span a wider liquid range in the course of operation.
In the case of differential locking devices, in order to reduce energy losses, in the disconnected state of the differential locking device the control signal does not only fix the basic position of the regulating slide valve but simultaneously triggers the artificial increase of the cross-section of the changing measuring throttles. In technical literature this solution is known as a relieving connection.
The operation described above can be realized with a known device which contains a small-sized controlled check-valve and a combination of permanent throttles arranged in by-pass control pipelines of small cross-section.
With drives of impellers erroneous synchronization does not result only from the difference of the required torque arising from the interaction between a wheel and the ground which can be compensated by operating the current divider functioning as a connected differential locking device, by the the artificial loads imposed by the accessory throttles, but also the tires with different pressures and diverse diameters which may be unevenly worn, and the different radii of turning, so that the equally distributed liquid flows arriving at the diversely adjusted hydromotors may cause a deviation in the number of revolutions.
As a consequence of the weight and inertia of the vehicle, a mechanical connection, i.e. wheel-ground-wheel is also established, and the synchronization error caused by a secondary factor will not appear primarly as a difference in the number of revolutions but as a control signal for positive recoupling, forwarded to the flow divider and as a consequence, by the sudden reaching of the capacity limit of the pump, the vehicle stops.